DOC: promex: Add missing backend metrics
"haproxy_backend_agg_server_status" and "haproxy_backend_agg_check_status"
were not referenced in promex README.
"haproxy_backend_agg_server_check_status" is also missing but it is a
deprecated metric. Thus, it is better to not reference it.
diff --git a/addons/promex/README b/addons/promex/README
index e41ebdc..4e29e23 100644
--- a/addons/promex/README
+++ b/addons/promex/README
@@ -286,6 +286,8 @@
| haproxy_backend_max_total_time_seconds |
| haproxy_backend_internal_errors_total |
| haproxy_backend_uweight |
+| haproxy_backend_agg_server_status |
+| haproxy_backend_agg_check_status |
+-----------------------------------------------------+
* Server metrics